Glucoamylase (1,4-alpha-D-glucan glucohydrolase, EC 3.2.1.3) is an enzyme, which catalyzes the release of D-glucose from the non-reducing ends of starch or related oligo- and polysaccharide molecules.
Commercially, glucoamylases are used to convert starchy material, which may already be partially hydrolyzed, e.g., by an alpha-amylase, to glucose. The glucose may then be converted directly or indirectly into a fermentation product, such as ethanol, using a fermenting organism. The end product may also be syrup. For instance, the end product may be glucose, but may also be converted, e.g., by glucose isomerase to fructose or a mixture of glucose and fructose. Glucoamylases are produced by several filamentous fungi and yeast including Aspergillus niger. 
WO 99/28448 concerns a glucoamylase derived from Talaromyces emersonii and the use thereof for producing fermentation products.
WO 2006/069289 discloses a glucoamylase derived from Trametes cingulata, Pachykytospora papyracea and Leucopaxillus giganteus and the use thereof in processes for manufacturing fermentation products.
The present invention provides variants of parent glucoamylases with improved properties compared to its parent. More specifically it is an object of the present invention to provide glucoamylase variants which provide a higher saccharification yield and yield in fermentation product production processes, such as ethanol production processes, including conventional ethanol production processes based on gelatinized starch-containing material and/or raw starch hydrolysis (RSH) processes (i.e., one-step ethanol fermentation processes) based on un-gelatinized (or uncooked) starch.